Just take the signs off and throw them away if you can.
If they are on the outside of a door hit it on the way in if you see a trashcan near by. If they are on the inside or you don't see a trashcan then grab it on the way out.
If the sheep don't see signs to reinforce the fear narrative and they become less afraid.
I've been doing this for the last month and most places haven't replaced them.
It's a simple act of rebellion against tyranny.
And yes, stealing is illegal but so was the American Revolution. Grow a pair and fight.
Zoom out. Many places are corporates chains that put the signs up at direction of a central HR months ago. Also small stores at malls and shopping plazas have no control over the signs up up at the main entrances. Once the signs are taken down they typically won't replace them.
Many smaller businesses have had the signs up the whole time. Removing them is sometimes all the incentive they need. You're just giving them a push in the right direction.
Going somewhere else doesn't help the sheep. Be proactive, not passive.